Leak between Master Cylinder and Brake booster

Maintenance advice to keep your Spider in shape.
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aevansgatech
Posts: 346
Joined: Mon Jul 27, 2015 2:51 pm
Your car is a: 1982 Spider 2000

Leak between Master Cylinder and Brake booster

Postby aevansgatech » Fri Feb 17, 2017 7:42 pm

Came upon a frustrating issue while bleeding my brakes.

I'm losing brake fluid and the only spot I can really see it start to pool is between the brake master cylinder and the brake booster. I never had it off, I only replaced the feed lines from the reservoir, so it's hard to imagine what is going wrong. Is there a gasket in between the master cylinder and the booster which may be compromised?

On top of that, I am able to successfully bleed the brakes (calipers) and the pedal is firm, so it seems to be an issue on the feed side.
1979 Spider 2000 (gone)
1984 Pininfarina Azzurra (for sale)
1982 Spider 2000 (here to stay)

ORFORD2004
Posts: 1099
Joined: Wed Mar 17, 2010 9:48 pm
Your car is a: 1983 PININFARINA
Location: Sherbrooke, Qc, Canada

Re: Leak between Master Cylinder and Brake booster

Postby ORFORD2004 » Fri Feb 17, 2017 9:11 pm

Is there a gasket in between the master cylinder and the booster which may be compromised?

No, change your MC.

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nelsonj
Posts: 394
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Your car is a: 1972 Spider 124

Re: Leak between Master Cylinder and Brake booster

Postby nelsonj » Fri Feb 17, 2017 10:54 pm

After you change your master cylinder, only then will you learn the true joy of bleeding, really bleeding, your breaks. There must be a better way than what I went through...
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aevansgatech
Posts: 346
Joined: Mon Jul 27, 2015 2:51 pm
Your car is a: 1982 Spider 2000

Re: Leak between Master Cylinder and Brake booster

Postby aevansgatech » Sat Feb 18, 2017 8:41 am

thanks guys, somehow my MC went bad over the winger then :x

is it worth getting a power brake bleeder? I'm assuming that takes care of air in the MC and the lines
1979 Spider 2000 (gone)
1984 Pininfarina Azzurra (for sale)
1982 Spider 2000 (here to stay)

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RRoller123
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Your car is a: 1980 FI SPIDER 2000
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Re: Leak between Master Cylinder and Brake booster

Postby RRoller123 » Sun Feb 19, 2017 7:53 am

I am just about to undertake this too, MC including the booster. Is there a trick to getting the MC started in the bleeding process, without making a bloody mess everywhere?
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DieselSpider
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Joined: Wed Dec 24, 2014 10:21 pm
Your car is a: 1978 124 Spider with Isuzu Turbo Diesel

Re: Leak between Master Cylinder and Brake booster

Postby DieselSpider » Mon Feb 20, 2017 7:13 am

You can bench bleed the master cylinder however that is more difficult when they do not have a built in reservoir. Myself I finally a few years ago I did something I should have done 45 years ago and that was pickup a MityVac Vacuum Bleeder. Best $29 I ever spent.

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aevansgatech
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Joined: Mon Jul 27, 2015 2:51 pm
Your car is a: 1982 Spider 2000

Re: Leak between Master Cylinder and Brake booster

Postby aevansgatech » Wed Feb 22, 2017 12:56 pm

DieselSpider wrote:You can bench bleed the master cylinder however that is more difficult when they do not have a built in reservoir. Myself I finally a few years ago I did something I should have done 45 years ago and that was pickup a MityVac Vacuum Bleeder. Best $29 I ever spent.


Do you use the vacuum bleeder at the caliper bleed screws or do you need to use the vacuum bleeder on the MC first?

I don't understand how to connect to the MC outlet ports when the MC is out of the vehicle.
1979 Spider 2000 (gone)
1984 Pininfarina Azzurra (for sale)
1982 Spider 2000 (here to stay)

DieselSpider
Posts: 2130
Joined: Wed Dec 24, 2014 10:21 pm
Your car is a: 1978 124 Spider with Isuzu Turbo Diesel

Re: Leak between Master Cylinder and Brake booster

Postby DieselSpider » Wed Mar 01, 2017 5:14 am

aevansgatech wrote:
DieselSpider wrote:You can bench bleed the master cylinder however that is more difficult when they do not have a built in reservoir. Myself I finally a few years ago I did something I should have done 45 years ago and that was pickup a MityVac Vacuum Bleeder. Best $29 I ever spent.


Do you use the vacuum bleeder at the caliper bleed screws or do you need to use the vacuum bleeder on the MC first?

I don't understand how to connect to the MC outlet ports when the MC is out of the vehicle.


There are plenty of adapters that came with the MityVac Kit however with a vacuum bleeder you can skip the bench bleeding of the master cylinder. On the Spider bench bleeding is a bit more difficult since the reservoir is mounted on the fire wall.


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